[SOLVED] largest numbers from an array

ChozN · 03-21-2012, 07:15 PM

I need to calculate the biggest number in array size n.
Example: Users enter: 1 7 4 9
The biggest number is : 9
Simple but I'm really new on this on Shell/Bash! Anything will be great! Thanks!

Code:

#!/bin/bash 

printf "\tEnter a list of numbers, with spaces: "
read -a ARRAY

BIG=$1
for i in ${!ARRAY[@]} ; do
    if [ $i -gt $BIG ] ; then
        BIG=$i
    fi
done

echo "Largest number is $BIG"

ChozN · 03-21-2012, 08:36 PM

solved please closed this thread! Thanks anyways!

grail · 03-22-2012, 12:54 AM

Please show solution for others and then you can mark as SOLVED yourself

ChozN · 03-22-2012, 02:13 AM

Code:

#!/opt/local/bin/bash
# get the biggest number in an array of integers

declare -a list # array of integers
declare -i biggest # biggest number of the array
declare -i current # current element of the array

read -a list -p "Enter each integer element separated by white spaces: " 
size=${#list[@]}

biggest=${list[0]} # first element of the array is supposed to be the biggest one
for current in ${list[@]}; do # loop through the array
    if [ $current -gt $biggest ]; then
        biggest=$current
    fi
done

echo -e "\nThe biggest integer number in the array is: $biggest";

This is one way to solution from [chapeupreto] on other forum!

grail · 03-22-2012, 03:18 AM

Or maybe a little simpler:

Code:

#!/bin/bash

read -a list -p "Enter each integer element separated by white spaces: "

echo "The largest number is: $(printf "%d\n" ${list[@]} | sort -n | tail -n1)"

David the H. · 03-22-2012, 11:18 AM

I'd personally prefer the in-shell solution, as long as the number list isn't huge.

The if statement could be shortened to a single line though, and it should ideally be using an arithmetic expression test instead.

If you loop through the array index numbers you can get the position as well as the value.

Code:

biggest=${list[0]} position=0

for i in "${!list[@]}"; do
	(( ${list[i]} > biggest )) && biggest=${list[i]} position=$i
done

echo "Largest value is $biggest (Array entry no: $position)"

Finally, it might be a good idea to include a test for non-integer input first.